The Miami-based cruise company announced the agreement with Germany’s Meyer Werft shipyard on Monday. The newest 164,600-ton “Breakaway Plus” ships will cost a total of about 1.6 billion euros, or about $2.18 billion.

The newest ships are scheduled to be delivered in the second quarter of 2018 and fourth quarter of 2019. Norwegian, which took delivery of Norwegian Breakaway last year and Getaway in February, is also awaiting Norwegian Escape in the fall of 2015 and Norwegian Bliss in spring of 2017.

Norwegian will pay approximately 15 percent more for the new ships than for Escape and Bliss, also in the “Breakaway Plus” class, said UBS Investment Research leisure analyst Robin Farley in a note to investors. Farley wrote that the order was “somewhat unexpected at the moment given how much time there is to order for deliveries that far in advance.”

Kevin Sheehan, president and CEO of Norwegian, said the newer ships will cost more for a variety of reasons, including the fact that shipyards have more business now than they did when the company placed its previous order.

“We were the guy ordering ships when every shipyard was dying for orders,” he said. “We had a lot of leverage there.”

The two new ships are in the same class as Escape and Bliss — larger versions of the nearly 4,000-passenger Breakaway and Getaway. But Sheehan said that the still-unnamed vessels will have features that make them “quite a bit different.” The added “bells and whistles” also contributed to the higher price, he said, without revealing any details.

Norwegian Escape will sail the Caribbean from its home port of Miami when it launches next year, joining Getaway. Deployment plans for the following ships have not been released.

With the latest order, Norwegian will grow its fleet to 17 ships by 2019.

The agreement is just the latest announced for large new cruise ships in the past few months. In March, European cruise line MSC Cruises said it was ordering two 4,500-passenger vessels to be delivered in 2017 and 2019; the company followed up in May with an announcement for two new 4,100-passenger ships coming in 2017 and 2018. Royal Caribbean Cruises said in May that it was ordering a fourth 5,400-passenger Oasis-class ship for arrival in 2018.